The present invention relates to a novel one component room temperature setting composition having an excellent storage stability.
Compositions containing as a main component a urethane resin, an epoxy resin or a silicone resin have been known as room temperature setting compositions. They are used as paints, coating compositions, sealing materials, adhesives, casting materials, and the like. These room temperature setting compositions cause a crosslinking reaction at temperatures in the vicinity of room temperature to form cured coatings. Most of them are of a two component type that one component is admixed just before use with another component having a functional group capable of forming crosslinking points. In case of such a two component setting composition, a main component must be admixed with a hardener prior to the use in a predetermined ratio, and moreover, the mixture must be used up in a certain pot life, because the residue is hardened and is not usable later.
Two component setting compositions require troublesome work in weighing and admixing upon use, and also troubles such as error in weighing are liable to occur. From this point of view, one component setting compositions are convenient for use, and also are profitable in saving of resources.
Further, in many cases, room temperature setting compositions contain additives such as pigments, fillers, ultraviolet absorbents, antioxidants and other additives in accordance with the objects of use. It is known that chemical characteristics of pigments, water content, impurities and so on have a great influence on the storage stability and workability of the compositions and the physical properties of the cured products.
The present inventors already found that a vinyl polymer having a hydrolyzable silyl group on the polymer chain end or the side chain not only has excellent properties such as gloss, weathering resistance and discoloration resistance which are characteristic of vinyl polymers, but also has excellent features such as an improved close adhesiveness to inorganic materials based on the hydrolyzable silyl group, and in particular, a crosslinkability at ordinary temperature by water, especially moisture in the atmosphere to form a dense network structure, thus providing a resin having excellent solvent resistance, water resistance, heat resistance, hardness and weathering resistance, as disclosed in Japanese Unexamined Patent Publication (Tokkyo Kokai) No. 36395/1979.
The above-mentioned vinyl polymer having a hydrolyzable silyl group admixed with a hardener and a pigment is crosslinkable by moisture, and is expected to provide a one component type room temperature setting composition. However, this composition is very poor in storage stability (can stability or shelf life). The hydrolyzable silyl group-containing vinyl polymer causes hydrolysis of the silyl end group even in the absence of a hardener, if moisture is present, and hardens while gradually forming siloxane bonds. In particular, the addition of an additive such as pigment or filler thereto lowers the storage stability due to water included therein. For instance, inorganic pigments such as titanium dioxide, iron oxide and chrome yellow and other many organic pigments usually contain about 0.2 to about 1% by weight of water. The water content of a pigment such as an iron oxide glazing color or carbon black reaches 5 to 10% by weight. It is troublesome in working to dehydrate these pigments prior to use by heating under reduced pressure. Also, incorporation of water into a composition may occur even at the time of opening and closing of a container in repeated use of the composition. Therefore, in order to make the composition be of practical value, it is necessary that the composition can maintain the stable state even if a certain amount of water is incorporated therein.
The primary object of the present invention is to provide a one component room temperature setting composition having an excellent storage stability.
This and other object of the present invention will become apparent from the description hereinafter.